Fix for 9905 - Investigate negative numbers on Summary's timeSinceLastAttempt field

[NicholasCouri]

Fix #9905 - Do not user server timestamp during the first summary.

[agarwal-navin]

I think it may be worth adding a comment somewhere that the timeSinceLastAttempt and timeSinceLastSummary for the first summary are basically time since the summarizer loaded. Maybe the place where we initialize these when attempting a summary?

[msfluid-bot]

⯅ @fluid-example/bundle-size-tests: +95 Bytes

Metric Name	Baseline Size	Compare Size	Size Diff
aqueduct.js	398.71 KB	398.73 KB	⯅ +19 Bytes
containerRuntime.js	220.31 KB	220.33 KB	⯅ +19 Bytes
loader.js	160.49 KB	160.49 KB	■ No change
map.js	235.41 KB	235.42 KB	⯅ +19 Bytes
matrix.js	323.31 KB	323.33 KB	⯅ +19 Bytes
odspDriver.js	182.42 KB	182.42 KB	■ No change
odspPrefetchSnapshot.js	77.23 KB	77.23 KB	■ No change
sharedString.js	343.89 KB	343.9 KB	⯅ +19 Bytes
Total Size	1.93 MB	1.93 MB	⯅ +95 Bytes

---

Baseline commit: 7574512

Generated by 🚫 dangerJS against 0d5b405